DESCRIPTION: (Adapted from the application) Partial support for a workshop on pathogenesis by non-acute retroviruses is requested. Viruses that cause cancer, immunodeficiencies and neuropathology will be considered, this includes murine leukemia viruses, avian leukosis virus, feline leukemia virus, murine mammary tumor virus, HTLV-1, bovine leukemia virus, MAIDS virus, endogenous human retroviruses, non-human lentiviruses and spumaviruses. The human viruses are of interest for their pathogenic or genetic properties. The other viruses provide important model systems for disease processes that are relevant to analogous human diseases. This is the ninth workshop in a series of workshops which began in 1986. These workshops are generally believed to contribute to the dissemination and cross-fertilization of ideas among scientists in this field. It is projected that 120 people will attend the workshop.